Use Antioch::constant_clone in TroeFalloff

This should fix #8
Merge pull request #9 from ddemidov/issue_8

Use Antioch::constant_clone in TroeFalloff
Forgotten test
lindeman_test back on
Macros for using auto iff C++11 is enabled
Use auto for VexCL max(a,b)
Trying to use auto for ChemicalMixture::X, failing

What's weird is that even after working around "trailing return
decltype doesn't support this", the exact same code that gives me a
good return value gives me a broken decltype value.  Need to try this
with clang and gcc 4.8...
Preparing for 0.0.6 tag.
Remove unused typedef to fix warning
Bugfix in C++11 asserts
With gcc 4.8.1 all works as it should.
Add Antioch shims for math functions

This is mostly a hideous trick to let trailing return functions with
decltype get Koenig lookup right.

But it'll let us easily play with stuff like fastapprox later too.
Trying to make some more functions auto

This is segfaulting, but at least it's compiling.  Still
investigating.
Enable returning auto only when safe
Update vexcl_utils

Instantiate return_auto as true, match the new raw_value_type API.
Reposition section marker
More auto functions
Minor refactor
More auto functions
Keep auto method defns in class declaration

This fixes our compatibility with gcc 4.7.  It looks like we'll need
to disable auto for gcc 4.6 and older.